View Full Version : Holey cow

01-19-2016, 03:58 AM

Have we been doing it wrong?

01-19-2016, 04:20 AM
Interesting. I wonder if there's something particular about the "f" shape or is it just the acoustic properties of an elongated sound hole. From the article, "the more elongated the sound hole, the more sound can escape..." If that's the case, then wouldn't a couple of simple, long, straight sound hole slots perform just as well?

01-19-2016, 04:30 AM
They're saying that the perimeter is more important, measured by airflow.
Air at the edge of a hole moves faster apparently? I guess that makes sense, since when you force air through a nozzle, it expands as it exits..... which means that the air at the outside has to move faster because it has to go farther (arc'd) than the air in the middle that went straight.

But then.. a c shape and a circle.. would have essentially the same perimeter since it's like.. a circle folded in half. I guess the arc idea would still apply, because there's less air being pumped in the middle, since it's all edge?


01-19-2016, 08:37 AM
Certainly the hole is not the only factor.
But... it's a factor that's often taken for granted, especially if it's not just an issue of area.
Area is a factor as well though.. since we have the math for port hole/volume frequency response.
But... as far as the claimed "radiated" power... that does seem like it would be an area of interest.

01-19-2016, 05:20 PM
The area of a sphere is an orange peel? Well, actually that is right, but it will never lie flat. See Mercator's projection. Interesting take on the F hole however. Interesting. They were into the music of the spheres so it makes sense. I think... I don't know diddly about violins or F holes, but my theory is that the F hole just looks right. It mimics the shape of the upper and lower bout and it relieves the air pressure in the box and everybody else just copied it because it is the perfect design.

01-19-2016, 06:10 PM
Violin is very math.
F-hole shape is derived from opposing golden/fibbonacci spirals.
The body shape, and the scroll work too. The brain unconsciously recognizes the proportions to look "right"
Almost a religious representation of math's relation to physical world.

This guy has a very detailed write up... that I don't pretend to understand.


I'm not convinced forcing an instruments design into a math sequence makes it better, but sometimes wierd things hit a mark all the same.